1. A Field of Invention
The use of black currant juice (Ribes nigrum L.) or black currant juice concentrate or dry extract thereof, to inhibit monoamine oxidase and to activate the brain and central nervous system, in a living animal, especially a human being, in need thereof, and thereby to increase the general cerebral performance, especially in healthy and elderly people, and for the prevention, treatment, and alleviation of neurodegenerative diseases associated with reduced cerebral performance, such as Parkinson's disease, dementia, and mood disorders, and compositions thereof for such purpose.
2. Background of the Invention and Prior Art
The neurotransmitter dopamine is one of the most essential cerebral neurotransmitters responsible for the modulation of cerebral performance.
Reduced dopamine concentrations, which are often present in elderly people and specific neurodegenerative diseases, are always associated with reduced cerebral function.
Unfortunately, the substitution of dopamine (which is the main target of L-dopa therapy) does not have the desired effect, since dopamine substitution supports the decay of dopaminergic neurons, thereby accelerating the loss in cerebral function.
As neuronal decay is also supported by biotransformation products of dopamine, treatment with dopamine metabolism inhibitors should be preferred.
One of the first steps of dopamine degradation is catalyzed through monoamine oxidases, the inhibition of which is one aim of any therapeutic intervention addressed thereto.
Within the framework of an extensive pharmacognostic screening of various plants and the extracts thereof, it has been found unexpectedly that the juice of black currant has monoamine oxidase (MAO)-inhibiting properties and a cerebro-activating effect.
In the patent literature, the black currant has already been mentioned in connection with an enhancement of cerebral performance (EPA 88305450.4; EP 0296751 A1). In contrast to the present invention, however, in this patent application the desired enhancement effect is directly ascribed to the kernel oil and the unsaturated essential fatty acids (e.g., gamma linolenic acid). Within the scope of the investigations relating to the present invention, however, it was demonstrated that the juice of black currant and its concentrates and dry extracts, which are employed according to the present invention, contain essentially no or only insignificant amounts of kernel oil or unsaturated fatty acids (C.sub.18, w3, 6, 9=0.02% and C.sub.18, w3, 6=0.0018% by weight), so that such materials do not contribute to the excellent MAO-inhibiting and cerebro-stimulating activities of the black currant juice according to the present invention.
On the contrary, it was demonstrated that black currant juice and concentrates and dry extracts thereof are characterized by MAO-inhibiting and cerebro-activating effects. According to these properties, black currant juice has the characteristic of enhancing cerebral performance in healthy and elderly people, and in patients suffering from neurodegenerative diseases, especially since it is believed that MAO-B inhibitors can halt the progression of such diseases, e.g., Parkinson's disease, for example, by preventing further degeneration of dopaminergic neurons. For details, inter alia, see SCRIP, May 1989, "Recent Trends in Research and the Treatment of Parkinson's Disease" by Professor William Armstrong (PJB Publications Ltd), cover sheet plus pages 58-61 and 63-67, in support of this relationship and the nexus between MAO-B inhibitory activity of a compound and its utility in the alleviation of neurodegenerative diseases associated with reduced cerebral performance.
Such desirable results have been substantiated by different test systems:
1. Demonstration of MAO-inhibiting action in vitro
2. Demonstration of MAO-inhibiting action in humans
3. Demonstration of stimulating effect in the mouse
4. Demonstration of cerebro-activating effect in the rat
5. Demonstration of cerebro-activating effect in humans
all as shown hereinafter under Pharmacological and Clinical Results.